In Russia, autumn reveals grey-green lichen patches and moss cushions on tree trunks once the canopy drops. While iron sulfate is a common remedy applied after leaf loss, experts note that these colorful growths do not always mean the tree is sick. Sometimes, simply removing dried fruit and inspecting the crown reveals how the tree survived the season without chemical intervention.[1]
Iron sulfate is specifically useful when a clear task exists, such as targeting diseases like scab on apples or rot on plums. However, it is not a universal cure and cannot reach infections hidden inside dead branches or mummified fruit. The substance leaves rusty stains on concrete, tiles, and metal that are difficult to remove. To prevent damage, gardeners cover walkways with plastic sheeting and protect evergreen shrubs like boxwood before spraying.[1]